Lipoprotein lipase (LPL) and hepatic triglyceride lipase (HTGL) are enzymes located on the surface of capillary endothelia. These two lipases act to remove triglyceride from the ore of circulating lipoprotein particles to initiate remodeling into smaller, denser forms. Xenical is a drug which, taken orally, inhibits gastric and pancreatic lipase activity by binding irreversibly to these enzymes to decrease intestinal fat absorption. Xenical may inhibit systemic lipases such as LPL and HTGL as well as gastrointestinal lipases. This study will investigate the effect of xenical and/or its metabolites on plasma LPL and HTGL activities in the fasted state and during the postprandial period.